Method for lubricating wave reduction gear, and rotating table device

Abstract

A wave reduction gear ( 5 ) is disposed inside a device case ( 2 ) of a rotating table device ( 1 ). Lubrication oil is sprayed from an oil supply channel ( 22 ), which is formed in the device case ( 2 ), toward an oil supply hole ( 22 ) formed in a cup-shaped flexible externally toothed gear ( 12 ). A wave bearing ( 19 ) disposed in the interior is lubricated via the oil supply hole ( 21 ). Lubricating oil that has entered into the flexible externally toothed gear ( 12 ) is forcibly suctioned to the exterior via an oil recovery channel ( 23 ) that is formed in the device case ( 2 ). Accordingly, it will be possible to prevent oil from being suctioned due to the negative pressure state in the interior of the flexible externally toothed gear accompanying the high-speed rotation, and regions of the wave bearing ( 19 ) can be reliably lubricated.

1. A method for lubricating a wave reduction gear, wherein lubricating oil is supplied to bearing components of a wave generator fitted inside a cup-shaped flexible externally toothed gear in a wave reduction gear disposed in a device case, and portions where the flexible externally toothed gear and a rigid internally toothed gear are enmeshed; wherein the lubricating method is characterized in comprising:
 forming at least one oil supply hole in a region of at least one of a cylindrical trunk part of the flexible externally toothed gear, and a diaphragm that defines a bottom part thereof; 
 spraying lubricating oil, which has been introduced from exterior of the device case, toward the region of the flexible externally toothed gear in which the lubricating oil supply hole is formed; 
 forcibly introducing lubricating oil into the flexible externally toothed gear via the oil supply hole; and 
 supplying the lubricating oil that has been forcibly introduced into the flexible externally toothed gear to the bearing components of the wave generator that is fitted in an open end part of the flexible externally toothed gear. 
 
     
     
       2. The method for lubricating a wave reduction gear according to  claim 1 ; characterized in comprising:
 forcibly suctioning the lubricating oil introduced into the device case toward the open end of the flexible externally toothed gear; 
 forcibly supplying the lubricating oil in the flexible externally toothed gear to the bearing components of the wave generator, and forcibly supplying lubricating oil, which has not entered the flexible externally toothed gear, from the oil supply hole to the enmeshed portions of the flexible externally toothed gear and the rigid internally toothed gear; and 
 recovering to the exterior of the device case lubricating oil that has been forcibly suctioned through the bearing components and the meshing portions. 
 
     
     
       3. A flexible externally toothed gear in a wave reduction gear used in the lubrication method of  claim 1 ; characterized in comprising:
 a cylindrical trunk part; a diaphragm that extends from one end of the cylindrical trunk part inward in a radial direction; and external teeth formed in an outer peripheral surface portion of the other open end of the cylindrical trunk part; wherein 
 at least one through-hole used for supplying oil is formed in a region of at least one of the cylindrical trunk part and the diaphragm. 
 
     
     
       4. A rotating table device, characterized in comprising:
 a device case; 
 a rotating table rotatably supported on the device case; and 
 a wave gear device, which rotates and drives the rotating table, and which is disposed in an interior space enclosed by the device case and the rotating table; wherein 
 the wave gear device has a rigid internally toothed gear, which is fixed to the drive case; a cup-shaped flexible externally toothed gear, which is coaxially connected to the rotating table; and a wave generator, which is fitted in an open end part of the flexible externally toothed gear; 
 the flexible externally toothed gear has at least one oil supply hole formed in a region of at least one of a cylindrical trunk part of the flexible gear, and a diaphragm that defines a bottom surface portion of the flexible gear; and 
 the device case has an oil supply channel for introducing lubricating oil from the exterior of the device case, and spraying the lubricating oil toward the region of the flexible externally toothed gear in which the oil supply hole is formed; and an oil recovery channel for forcibly suctioning the lubricating oil toward the open end of the flexible externally toothed gear, and recovering the lubricating oil to the exterior of the device case.